This invention relates to an oxygen mask assembly and, more particularly, to an oxygen mask assembly incorporating an improved oxygen dilutor assembly.
While routinely used in the intensive care setting, the use of noninvasive continuous positive airway pressure (CPAP) oxygen mask assemblies has experienced increasing familiarity and popularity in the hospital emergency room setting. The use of oxygen mask assemblies in emergency situations has proven advantageous because it avoids intubation and its associated risks of aspiration, infection, trauma, misplaced ET tubes, prolonged ventilation, and increased hospitalization and expenses. Moreover, the use of an oxygen mask assembly avoids the need for sedation, preserves speech and swallowing, improves oxygenation and decreases the physiologic work load on the heart.
U.S. Pat. No. 3,977,432 discloses one such oxygen mask assembly incorporating an oxygen dilutor including side wall apertures which allow for the entry of oxygen diluting air. A disadvantage associated with the assembly disclosed in U.S. Pat. No. 3,977,432 however is the tendency for the apertures in the dilutor side wall to become occluded when the dilutor contacts either the patient or the emergency personnel while the assembly is in use. Another disadvantage is that it does not incorporate any means for maintaining or adjusting continuous positive oxygen pressure.
It would thus be desirable to provide an oxygen mask assembly including, among other elements, an oxygen dilutor where the air inlet apertures are located thereon so that the risk of occlusion is minimized. It would also be desirable to provide a mask in which positive airway oxygen pressure can be maintained and adjusted. The present invention provides an oxygen mask assembly incorporating such an improved dilutor and mask.
An oxygen mask assembly embodying the present invention incorporating a dilutor with top wall apertures which minimize the risk of occlusion, a valve assembly for maintaining positive airway pressure, and a mask in which the pressure can be adjusted.
Particularly, the oxygen mask assembly includes a mask, a flexible hose having one end operatively connected to the mask, and an oxygen dilutor including an outlet connected to the opposite end of the hose and an oxygen inlet adapted for connection to an oxygen source. The dilutor includes an air inlet defined in a top wall thereof for diluting the oxygen flowing through the dilutor.
In one embodiment, the dilutor includes a head which includes the top wall and defines an interior cavity. The top wall includes an aperture and the dilutor further includes a rotatable port which covers the top wall of the head. The port includes an aperture adapted for rotatable alignment with the aperture in the top wall to define the air inlet. A jet extends unitarily outwardly from the top wall of the head. The jet defines the oxygen inlet and includes an interior conduit in fluid flow communication with the head cavity at one end and the oxygen source at the other end. A sleeve which extends upwardly from the top wall of the head surrounds the jet and is adapted for rotatable movement relative to the port and the jet. The sleeve includes a threaded inner surface which surrounds and is spaced from the jet and is adapted for threaded engagement with an oxygen supply hose.
In one embodiment, the oxygen mask assembly also includes an air reservoir bag assembly connected to the hose between the dilutor and the mask. The air bag assembly includes a connector with an interior surface defining a conduit having first and second inlet openings in fluid flow communication with and connected to the hose and a third opening in fluid flow communication with an air bag.
In the same embodiment, the oxygen mask assembly further includes a one-way inhalation valve assembly connected to the hose between the dilutor and the mask. The valve assembly includes a connector with an interior surface defining a conduit having first and second inlet openings in fluid flow communication with the hose and a third inlet opening in fluid flow communication with a one-way inhalation valve. The one-way valve assembly allows continuous positive airway pressure to be maintained in the mask.
Still further, in the same embodiment, the oxygen mask assembly includes a pressure valve assembly operably associated with and connected to the mask. The pressure valve assembly includes a body having an inlet in fluid flow communication with the interior of the mask and an outlet in fluid flow communication with the ambient air. The pressure valve assembly further includes a plunger covering the inlet, a cap threadingly secured to the top of the pressure valve assembly and a spring abutting the plunger and the cap respectively whereby the rotation of the cap results in the movement of the plunger towards or away from the inlet for adjusting the air pressure in the mask.
In one embodiment, the mask includes a frame with prongs thereon and a peripheral inflatable bladder which defines the face of the mask. The mask further includes a headband with straps having apertures therein adapted to receive the prongs on the frame for securing the headband to the mask.